From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: xiaosuo@gmail.com, kaber@trash.net, pablo@netfilter.org,
netfilter-devel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH] net: check the length of the data before dereferencing it
Date: Sun, 01 Apr 2012 23:29:42 -0400 (EDT) [thread overview]
Message-ID: <20120401.232942.1829187970291547571.davem@davemloft.net> (raw)
In-Reply-To: <1333336773.2325.6531.camel@edumazet-glaptop>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 02 Apr 2012 05:19:33 +0200
>> @@ -3845,6 +3845,8 @@ void tcp_parse_options(const struct sk_buff *skb, struct tcp_options_received *o
>> length--;
>> continue;
>> default:
>> + if (length < 2)
>> + return;
>> opsize = *ptr++;
>> if (opsize < 2) /* "silly options" */
>> return;
>
> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Tag Eric, you're it.
You ACK'd this patch, so you get to show how this is actually able
to cause some kind of problem.
I assert that this is adding a useless test, that doesn't fix any kind
of possible crash or misbehavior. If length == 1 at the default:, the
code will absolutely do the right thing.
Prove me wrong.
next prev parent reply other threads:[~2012-04-02 3:31 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-02 3:10 [PATCH] net: check the length of the data before dereferencing it Changli Gao
2012-04-02 3:19 ` Eric Dumazet
2012-04-02 3:29 ` David Miller [this message]
2012-04-02 3:45 ` Changli Gao
2012-04-02 3:53 ` Eric Dumazet
2012-04-02 3:57 ` David Miller
2012-04-02 3:59 ` Eric Dumazet
2012-04-02 4:47 ` Changli Gao
2012-04-02 4:54 ` Eric Dumazet
2012-04-02 6:27 ` Changli Gao
2012-04-02 6:43 ` Eric Dumazet
2012-04-02 3:45 ` Eric Dumazet
2012-04-02 3:55 ` David Miller
2012-04-02 3:58 ` Eric Dumazet
2012-04-02 4:14 ` David Miller
2012-04-02 3:19 ` David Miller
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